Michelle Dockery and John DineenJohn Dineen (L) and Michelle Dockery attend the Winter Whites Gala in aid of Centrepoint at Kensington Palace on November 26, 2013 in London, England.Michelle Dockery and John Dineen in the Royal Box on Centre Court at the All England Lawn Tennis and Croquet Club, Wimbledon, in 2014. Photo: Anthony Devlin/PA WireJohn Dineen (L) and Michelle Dockery attend the Winter Whites Gala in aid of Centrepoint at Kensington Palace on November 26, 2013 in London, England.VENICE, ITALY - SEPTEMBER 01: Michelle Dockery and John Patrick Dineen are seen leaving the Venice Airport during The 70th Venice International Film Festival on September 1, 2013 in Venice, Italy. (Photo by Jacopo Raule/FilmMagic)Michelle Dockery and John Dineen in 2014NEW YORK, NY - SEPTEMBER 06: John Dineen and Michelle Dockery watch the women's singles semifinal match between Serena Williams of United States of America and Na Li of China on Day Twelve of the 2013 US Open at USTA Billie Jean King National Tennis Center on September 6, 2013 in the Flushing neighborhood of the Queens borough of New York City. (Photo by Matthew Stockman/Getty Images)

Heartbroken Downton Abbey star Michelle Dockery is preparing to bid a heartbreaking farewell to her fiance today after spending her birthday making preparations for his funeral.

The Globe Globe winning actress flew to Ireland last week to be by her fiancé’s side in his last days.

John Dineen, from Cork, was diagnosed with a rare form of cancer earlier this year and Dockery (34) was with John and his family in his final moments on Sunday morning.

The actress marked a heartbreaking birthday today by making preparations for Mr Dineen's funeral.

John Dineen and Michelle Dockery in New York

Mr Dineen had been working as a Senior Director in FTI Consulting in London when he was diagnosed with cancer. He returned home to Ireland to spend time with his family and receive treatment at Marymount Hospice in Cork.

He also travelled to Germany for pioneering treatment after his diagnosis.

It is understood that the pair were engaged, and they started dating in September 2013 after being introduced by Irish actor Allen Leech, who stars alongside Michelle in the ITV period drama.

Dockery was with her fiancé and his family in his final hours and is said to have “gone to great lengths to support the family as much as possible.”

A requiem funeral mass will be staged tomorrow, with the family appealing for privacy.

News of their relationship hit the headlines earlier this year when it was reported that Michelle had been excitedly showing off her diamond ring during screen tests for the popular period drama.

The couple, who closely guarded their privacy, never commented publicly on their relationship.

In September 2014, Michelle said: “I have a wonderful man in my life from Ireland. We were introduced by Allen Leech. That’s all you need to know.” She even posted selfies on social media of her wearing the Munster rugby jersey.

Dineen was raised in Waterfall, Co. Cork and completed his undergraduate studies at University College Cork before completing a Masters in University College Dublin in 2005.

Ms Dockery, who played Lady Mary Crawley on the hit tv series, had been on a promotional tour for Downton Abbey in the US, which she cut short in order to be by John’s side.

Michelle Dockery and John Dineen in 2014

Dockery released a statement to WENN saying: "The family is very grateful for the support and kindness they have received but would kindly request that they are left to grieve in private."

The public relations company which Mr Dineen worked for, FTI Consulting, paid tribute to him.

The firm's UK head of strategic communications, John Waples, said colleagues were deeply saddened by his death and appealed for the family to be allowed to grieve in private.

"John was an immensely valued colleague and friend and will be sorely missed," he said.

"Our thoughts are with his fiancee Michelle, his family and friends, as well as our colleagues who were closest to him, and we ask for privacy for his family at this difficult time."